In this paper we review evidence from social, developmental, and evolutionary psychology to raise a common question: Are there priorities in how humans categorize their social world? Are some social groupings more prominent in childhood, and more resilient in adulthood than others? We review and compare evidence from each field, with a particular emphasis on exploring the relative robustness of gender, race, age, and language as social categories. We highlight the value of developmental approaches for characterizing the origins and nature of social categories in adults, and provide suggestions for how collaborative research from social, developmental, and evolutionary psychology could inform our understanding of potential priorities in social categorization. Copyright © 2010 John Wiley & Sons, Ltd.